From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 486B3ECE562 for ; Tue, 18 Sep 2018 00:06:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3431214C5 for ; Tue, 18 Sep 2018 00:06:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3431214C5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728849AbeIRFgS (ORCPT ); Tue, 18 Sep 2018 01:36:18 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:33451 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725928AbeIRFgS (ORCPT ); Tue, 18 Sep 2018 01:36:18 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1g23XE-0007JY-BK; Mon, 17 Sep 2018 18:06:32 -0600 Received: from [105.184.227.67] (helo=x220.Home) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA256:128) (Exim 4.87) (envelope-from ) id 1g23Wy-0002Qk-G9; Mon, 17 Sep 2018 18:06:32 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, Thomas Gleixner , Ingo Molnar , x86@kernel.org, "Eric W. Biederman" Date: Tue, 18 Sep 2018 02:05:27 +0200 Message-Id: <20180918000546.12552-1-ebiederm@xmission.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <87y3bzk6yv.fsf@xmission.com> References: <87y3bzk6yv.fsf@xmission.com> X-XM-SPF: eid=1g23Wy-0002Qk-G9;;;mid=<20180918000546.12552-1-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=105.184.227.67;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/DIl1OmWvEn2EtT0JxG07d8+Yrgb++rMU= X-SA-Exim-Connect-IP: 105.184.227.67 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [REVIEW][PATCH 01/20] signal: Simplify tracehook_report_syscall_exit X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace user_single_step_siginfo with user_single_step_report that allocates siginfo structure on the stack and sends it. This allows tracehook_report_syscall_exit to become a simple if statement that calls user_single_step_report or ptrace_report_syscall depending on the value of step. Update the default helper function now called user_single_step_report to explicitly set si_code to SI_USER and to set si_uid and si_pid to 0. The default helper has always been doing this (using memset) but it was far from obvious. The powerpc helper can now just call force_sig_fault. The x86 helper can now just call send_sigtrap. Unfortunately the default implementation of user_single_step_report can not use force_sig_fault as it does not use a SIGTRAP si_code. So it has to carefully setup the siginfo and use use force_sig_info. The net result is code that is easier to understand and simpler to maintain. Ref: 85ec7fd9f8e5 ("ptrace: introduce user_single_step_siginfo() helper") Signed-off-by: "Eric W. Biederman" --- arch/powerpc/include/asm/ptrace.h | 2 +- arch/powerpc/kernel/traps.c | 7 ++----- arch/x86/include/asm/ptrace.h | 2 +- arch/x86/kernel/ptrace.c | 11 +++++------ include/linux/ptrace.h | 17 +++++++++++------ include/linux/tracehook.h | 13 ++++--------- 6 files changed, 24 insertions(+), 28 deletions(-) diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index 447cbd1bee99..5b480e1d5909 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -149,7 +149,7 @@ do { \ #define arch_has_single_step() (1) #define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601)) -#define ARCH_HAS_USER_SINGLE_STEP_INFO +#define ARCH_HAS_USER_SINGLE_STEP_REPORT /* * kprobe-based event tracer support diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index c85adb858271..f651fa91cdc9 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -307,12 +307,9 @@ void die(const char *str, struct pt_regs *regs, long err) } NOKPROBE_SYMBOL(die); -void user_single_step_siginfo(struct task_struct *tsk, - struct pt_regs *regs, siginfo_t *info) +void user_single_step_report(struct pt_regs *regs) { - info->si_signo = SIGTRAP; - info->si_code = TRAP_TRACE; - info->si_addr = (void __user *)regs->nip; + force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)regs->nip, current); } static void show_signal_msg(int signr, struct pt_regs *regs, int code, diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 6de1fd3d0097..e353f08b7fe2 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -263,7 +263,7 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, #define arch_has_block_step() (boot_cpu_data.x86 >= 6) #endif -#define ARCH_HAS_USER_SINGLE_STEP_INFO +#define ARCH_HAS_USER_SINGLE_STEP_REPORT /* * When hitting ptrace_stop(), we cannot return using SYSRET because diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index e2ee403865eb..94bd6e89129a 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -1382,12 +1382,6 @@ static void fill_sigtrap_info(struct task_struct *tsk, info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL; } -void user_single_step_siginfo(struct task_struct *tsk, - struct pt_regs *regs, - struct siginfo *info) -{ - fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info); -} void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code, int si_code) @@ -1399,3 +1393,8 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, /* Send us the fake SIGTRAP */ force_sig_info(SIGTRAP, &info, tsk); } + +void user_single_step_report(struct pt_regs *regs) +{ + send_sigtrap(current, regs, 0, TRAP_BRKPT); +} diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 4f36431c380b..1de2235511c8 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -336,14 +336,19 @@ static inline void user_enable_block_step(struct task_struct *task) extern void user_enable_block_step(struct task_struct *); #endif /* arch_has_block_step */ -#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO -extern void user_single_step_siginfo(struct task_struct *tsk, - struct pt_regs *regs, siginfo_t *info); +#ifdef ARCH_HAS_USER_SINGLE_STEP_REPORT +extern void user_single_step_report(struct pt_regs *regs); #else -static inline void user_single_step_siginfo(struct task_struct *tsk, - struct pt_regs *regs, siginfo_t *info) +static inline void user_single_step_report(struct pt_regs *regs) { - info->si_signo = SIGTRAP; + siginfo_t info; + clear_siginfo(&info); + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = SI_USER; + info.si_pid = 0; + info.si_uid = 0; + force_sig_info(info.si_signo, &info, current); } #endif diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 05589a3e37f4..40b0b4c1bf7b 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -123,15 +123,10 @@ static inline __must_check int tracehook_report_syscall_entry( */ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step) { - if (step) { - siginfo_t info; - clear_siginfo(&info); - user_single_step_siginfo(current, regs, &info); - force_sig_info(SIGTRAP, &info, current); - return; - } - - ptrace_report_syscall(regs); + if (step) + user_single_step_report(regs); + else + ptrace_report_syscall(regs); } /** -- 2.17.1